formulas(sos).
all x (Object(x)-> (World(x)<->Situation(x)& (exists y (Point(y)& (all p (Proposition(p)-> (TrueIn(p,x)<->True(p,y)))))))).
all x (World(x)->Object(x)).
all x (Object(x)-> (Possible(x)<->Situation(x)& (exists y (Point(y)& (all p (Proposition(p)-> (TrueIn(p,x)->True(p,y)))))))).
end_of_list.